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Urban consolidation fallacies

A "concern for loss of bushland and heritage" is often interpreted to mean stopping the urban sprawling of Sydney. It is claimed that if we cease new housing development in areas like west of Liverpool and the Kellyvilles of this world, we can stop the urban sprawl, and that we need to make a few sacrifices and increase our urban density.

"How else are we going to cope with an ever expanding population?" it is asked, "unless each area takes its share in increasing urban densities". It is argued that to encourage people to use public transport/ bicycles then things need to be more compact not spread out.

This is a frequently mentioned misconception.

If the population has to increase, there are only two ways in which this can be accommodated. Either cram people closer together or spread out over a larger area. The question is, which is least detrimental?

Even with higher population densities, many areas of Sydney would not shrink. Such activities as business districts, public buildings, factory areas, airports, main roads, shops and hospitals would remain the same. These probably total 60% of the city's area. We have made a rough estimate what the effect would be of increasing by 15% the density of people living in the 40% residential balance. That is, where 100 people are currently living, 115 will be forced to live. This would have major deleterious effects on the city (as congestion increases very rapidly with increasing densities). However cramming 15% more people into the 40% residential area would save only 5% of Sydney's area.

Taking Sydney currently as a semi-circle 60 km across, the new distance across Sydney would be 58.4 km. This is, a saving of only 1.5 km from one end of the city to the other. In reality due to restrictions in some directions, the expansion would not be even over the perimeter but the concept is not changed. Even if, in some horrendous scenario one doubled the number of people (200 people living where 100 live now), the saving would be only 6 km! Refer to the attached diagrams.

You only need to look out the window when you fly from one of the capital cities to Sydney to confirm this calculation. As you fly, you pass over vast tracts of farmland and bushland. Finally when you arrive at the edge of the city, travelling from the edge to landing at the airport takes only a few moments. One does not wish to impinge on any bushland at all, but if an increasing population has to be accommodated one has to choose the lesser of the two evils. A negligible proportion of available farmland and bushland in Australia is saved compared to horrendously increasing the number of people in our residential areas.

What people usually fail to notice is the urban bushland that urban consolidation is surrepetiously destroying. Sydney at present has many pockets of remnant bushland. These are attractive to residents and visitors. They counteract pollution, mitigate run-off, cool the city and provide a sanctuary for wildlife. But the State Government appears to see them as merely an opportunity for medium- and high-density development. They are continually under siege by developers. They, together with suburban trees and gardens are much more valuable to Sydney residents than the 900 metres of fringe farmland and market gardens which is equivalent to the area claimed to have been saved by urban consolidation so far.

It is difficult to understand how such destruction can equate with a policy of "achieving the essential balance between the environment and development" . If so little peripheral bush would be saved, surely it is better for city people to live among some trees, birds and animals and to preserve these as far as is practical so as to prevent their extinction in the city area. Surely it is better for people to be able, if they so wish, to look out upon nature and to grow some fruit and vegetables themselves than to live shoe-horned in a concrete jungle, with little or no contact with trees or the growing of food.

Transport — the reality

Contrary to the assertions of the Department of Urban Affairs and Planning, it has been proved many times that higher densities produce higher concentrations of traffic, not less traffic and that any expanded use of public transport is at best minimal.

The increased congestion resulting from a higher density of people more than counteracts the effect of any increased public transport or bicycle use (which is very low). An important factor to be borne in mind is that more than 80% of car trips made are not work-related. Therefore even if a greater proportion of people in a high density situation were to use public transport to work, their use of cars for journeys to transport children, sport, entertainment and visiting will result in more congestion because there are more people in a given area. It should be noted that families are high users of public transport. To replace family homes located near railway stations with multi-density units occupied by young adults and rich empty nesters could actually reduce the number of train trips undertaken.

The Mayor of Leichardt, Maire Sheehan, said at a recent rally that use of public transport in her municipality has decreased in spite of substantial Medium-Density development. Complaints about parking and increased congestion problems indicate that almost all medium-density occupants have cars and use them

In spite of repeated requests the Department of Urban Affairs and Planning has not quoted one high-density city comparable to Sydney that does not experience severe traffic congestion. The central city of Paris experiences severe congestion; the average vehicle speed is only 20 km per hour. Yet Paris has high-density living, no freeways and one of the world's most intensive rail transit systems. Portland, in the United States is often cited as the most advanced model of a high-density development plan. It has high-density housing patterns, an extensively expanded light rail system, a public bus transport system provided with bicycle carriers and heavy restrictions on road development. Instead of traffic decreasing, Portland's traffic congestion is already approaching that of New York.

To demonstrate a correlation in complex situations, multi-variate analysis is preferable to looking at only two variables as urban consolidation proponents have done. Such analysis shows that any direct effect of high density on greater use of public transport is negligible, the only significant correlating factors of such use are accessibility of destination and family income - if one can afford a car one will choose to use it instead of the less convenient public transport. Planners need to take into account what people actually do rather than what they think they should do. High density increases traffic congestion. It remains completely unclear how high density can be claimed to improve Sydney's air quality.

The real self-interest club appears to be the developers for whom urban consolidation is very remunerative. They build profitable multi-units - more so than if development were to be on the fringe as existing buildings have to be torn down and therefore extra units created to replace those displaced. The government thinks it will save money in avoiding building new suburbs, it also belongs to this club. If the population has to increase what Sydney requires instead is some genuine planning based on properly substantiated principles.

The alternative of greenfields development on the fringe provides a wonderful opportunity to prevent the mistakes of the past. It is more cost-efficient to provide new infrastructure on a clean slate than to upgrade existing services which is necessary if densities are to be increased. It is hardly likely that previous administrations would have had the funds to methodically build any significant over-capacity into the infrastructure then constructed. Upgrading existing infrastructure is hampered by inefficiency of scale of operations, physical obstructions, legal constraints and problems associated with obsolescent engineering. The cost if this will be born by the users - you and I in the form of increased tariffs. The government thus can hide the real cost from the public.

Greenfields features could include a high standard of design and amenity, energy efficiency, prevention of pollution, the protection of environmentally sensitive areas and accessibility. Significant energy saving features could be embodied, bicycle tracks could be incorporated, water could be reused, power and communication cables installed underground, facilities, shops, job opportunities and transport such as rapid transit could be effectively integrated - not forgetting Sydney's characteristic of areas of open space.



Consider Sydney as a semicircle bounded by the sea on the Eastern side. Assume a 15% INCREASE IN DENSITY (i.e. 115 people live where 100 live now). Residential Saving of 1.6 km off 60 km city radius.

"Major facilities" include the CBD, freeways and major roads, large open spaces, industrialised areas, airports and other such facilities. These encompass an estimated 60% of the city area which does not vary significantly as population density increases. In reality they are dotted around in the city area but for simplifying presentation purposes are depicted as aggregated together in one block.

"Residential" includes dwelling blocks and other variable features such as access roads and small open spaces. This comprises an estimated 40% of the city area and will decrease as population density increases. For simplifying presentation purposes they are shown aggregated into one arc.

For a 100% INCREASE IN DENSITY (i.e. 200 people live where 100 live now), a Residential Saving of 6 km off the 60 km city radius would result.

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